Help Using GPS Location

[robothito]

Hello. I am now learning how to use Location when developing an App and I would like some help here.
(Following the android recipes book) I built an app using Androd Studio in which the java file is like this:

public class MyActivity extends AppCompatActivity {

    LocationManager manager;
    Location currentLocation;


    TextView locationView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_activity);

        locationView=(TextView)findViewById(R.id.locationView);

        manager= (LocationManager)getSystemService(Context.LOCATION_SERVICE);
    }


    @Override
    public void onResume() {
        super.onResume();
        if(!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
            //Ask the user to enable GPS
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setTitle("Location Manager");
            builder.setMessage("We would like to use your location, but GPS is currently disabled.\n"
                    +"Would you like to change these settings now?");
            builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    //Launch settings, allowing user to make a change
                    Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                    startActivity(i);
                }
            });
            builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    //No location service, no Activity
                    finish();
                }
            });
            builder.create().show();
        }
        //Get a cached location, if it exists
        currentLocation = manager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        updateDisplay();
        //Register for updates
        int minTime = 5000;
        float minDistance = 0;
        manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, minTime, minDistance, listener);
    }

    private void updateDisplay() {
        if(currentLocation == null) {
            locationView.setText("Determining Your Location...");
        } else {
            locationView.setText(String.format("Your Location:\n%.2f, %.2f",
                    currentLocation.getLatitude(),
                    currentLocation.getLongitude()));
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        manager.removeUpdates(listener);
    }

    //Handle Location callback events
    private LocationListener listener = new LocationListener() {

        @Override
        public void onLocationChanged(Location location) {
            currentLocation = location;
            updateDisplay();
        }

        @Override
        public void onProviderDisabled(String provider) { }

        @Override
        public void onProviderEnabled(String provider) { }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) { }

    };
}

It is basically the same code of the book with a little change in the textView and build from scratch (that is another question I am going to ask- but let's forget about that now)

1) Anyway, First thing I notice : in the methods of manager (which is a LocationManager) they all get a red underline. When I check it with the mouse it says: "Call requires permission which might be rejected by the user: code should explicitly check to see if permission is available (with checkPermission) or explicitly handle a potential SecurityException".

I have inserted this in the manifiest

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
    <uses-permission android:name="android.permission.INTERNET"></uses-permission>

And as you see in the code, it asks for the user to activate GPS if is disabled so what is the problem here?

2) I tried to run this example in the AVD of android studio. It stopped immediately (could not see anything). The android monitor has a lot of messages I don't understand.
Then I activate genimotion and when running the app there, I could see the program in motion and successfully do what is does (which is very simple, just put the (simulated) GPS value on screen)

3) I am worried about the amount of messages on the Android Monitor and in the RUN screen. (in this one, there is a lot of messages in dark red for example:

Failed to sync vcpu reg
Failed to sync vcpu reg
EAX=00000000 EBX=00000000 ECX=00000000 EDX=00000663
ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
EIP=0000fff0 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300
CS =f000 ffff0000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 0000ffff
IDT=     00000000 0000ffff
CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000
DR6=ffff0ff0 DR7=00000400
EFER=0000000000000000
Failed to sync vcpu reg
Failed to sync vcpu reg
EAX=00000000 EBX=00000000 ECX=00000000 EDX=00000663
ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
EIP=0000fff0 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300
CS =f000 ffff0000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 0000ffff
IDT=     00000000 0000ffff
CR0=60000010 CR2=00000000 CR3=00000000 CR4=00000000
DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000
DR6=ffff0ff0 DR7=00000400
EFER=0000000000000000
Failed to sync vcpu reg
Failed to sync vcpu reg
EAX=00000000 EBX=00000000 ECX=00000000 EDX=00000663
ESI=00000000 EDI=00000000 EBP=00000000 ESP=00000000
EIP=0000fff0 EFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 00000000 0000ffff 00009300
CS =f000 ffff0000 0000ffff 00009b00
SS =0000 00000000 0000ffff 00009300
DS =0000 00000000 0000ffff 00009300
FS =0000 00000000 0000ffff 00009300
GS =0000 00000000 0000ffff 00009300
LDT=0000 00000000 0000ffff 00008200
TR =0000 00000000 0000ffff 00008b00
GDT=     00000000 0000ffff

which I don't understand. I wonder if there is something wrong

4) and lastly, I deactivated the (simulated)GPS in genimotion and still the activity shows the last value. it does not show me the message to activate even though that is explicitly in onResume(). I wonder what is wrong here

Any help greatly appreciated